| 摘要 |
947, 735. Programmed control of steam turbines. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Sept. 17, 1962 [Sept. 21, 1961], No. 33874/61. Heading G3N. In a programmed running-up arrangement for a steam turbine a steam supply valve is positioned by a velodyne, comprising an amplifier supplying a motor driving a reduction gear-box with negative feedback being applied to the input of the amplifier from a tachogenerator driven by the motor. An input to the velodyne is provided through a run-up amplifier from a differential amplifier having an output dependent on a companion between a turbine speed current, derived through a rectifier from a tachogenerator driven by the turbine and a reference current from a rectifier, such as a magslip or synchro, positioned by a velodyne having an input from a pre-set voltage source through a run-up switch so that the reference current increases linearly with time. The run-up switch is opened by a hold relay when limiting conditions, sensed by eccentricity, vibration, vacuum and temperature devices, are exceeded. A run-down relay is also actuated by the device which closes a run-down switch in a feedback loop from the differential amplifier to the reference velodyne so as to keep the reference current in step with the turbine speed and also isolates the input to the steam valve velodyne. A transducer connected between the inlet and exhaust of the turbine gives an output which is fed back in a negative sense to the amplifier of the steam valve velodyne to provide a rapid response negative feedback for stabilizing the speed-control. The programme can be varied by timed adjustment of the pre-set voltage or by successively employing velodynes having different characteristics. |
